U.S. patent application number 14/865906 was filed with the patent office on 2016-12-15 for multiple variable valve lift apparatus.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Byong Young CHOI.
Application Number | 20160363011 14/865906 |
Document ID | / |
Family ID | 56021228 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160363011 |
Kind Code |
A1 |
CHOI; Byong Young |
December 15, 2016 |
MULTIPLE VARIABLE VALVE LIFT APPARATUS
Abstract
A multiple variable valve lift apparatus may include a camshaft
rotating by driving of an engine, a cam portion formed in a
cylindrical shape having a hollow that the camshaft is inserted
into, rotating together with the camshaft, configured to move along
an axial direction of the camshaft, and forming a zero cam and a
normal cam, a valve opening/closing device configured to be
operated by at least one of the zero cam or the normal cam which
are formed at the cam portion, an operating device disposed on an
exterior circumference of the camshaft so as to move together with
the cam portion, and a solenoid configured to selectively move the
operating device along an axial direction of the camshaft, in which
a journal, which has a radius being equal to a radius of the zero
cam, is formed at the cam portion.
Inventors: |
CHOI; Byong Young;
(Bucheon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
56021228 |
Appl. No.: |
14/865906 |
Filed: |
September 25, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 2013/0052 20130101;
F01L 1/047 20130101; F01L 2013/101 20130101; F01L 1/344 20130101;
F01L 9/04 20130101; F01L 13/0036 20130101; F01L 2013/001 20130101;
F01L 13/0005 20130101; F01L 1/053 20130101; F01L 1/181 20130101;
F01L 2001/0473 20130101; F01L 2810/02 20130101; F01L 13/0042
20130101; F01L 1/185 20130101; F01L 2305/00 20200501; F01L 1/18
20130101; F01L 1/12 20130101; F01L 2001/0476 20130101; F01L 13/00
20130101 |
International
Class: |
F01L 1/344 20060101
F01L001/344; F01L 9/04 20060101 F01L009/04; F01L 1/047 20060101
F01L001/047 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 12, 2015 |
KR |
10-2015-0083556 |
Claims
1. A multiple variable valve lift apparatus comprising: a camshaft
rotating by driving of an engine; a cam portion formed in a
cylindrical shape having a hollow that the camshaft is inserted
into, rotating together with the camshaft, configured to move along
an axial direction of the camshaft, and forming a zero cam and a
normal cam; a valve opening/closing device configured to be
operated by at least one of the zero cam or the normal cam which
are formed at the cam portion; an operating device disposed on an
exterior circumference of the camshaft so as to move together with
the cam portion; and a solenoid configured to selectively move the
operating device along an axial direction of the camshaft, wherein
a journal, which has a radius being equal to a radius of the zero
cam, is formed at the cam portion such that a cam cap surrounds an
exterior circumference thereof.
2. The multiple variable valve lift apparatus of claim 1, wherein
the operating device is formed in a cylinder shape having a hollow
that the camshaft is inserted into.
3. The multiple variable valve lift apparatus of claim 2, wherein:
a guide rail is formed at the operating device by a groove shape to
be extended along an external circumference, an operating pin,
which is selectively contacted to the guide rail, is disposed at
the solenoid, and the guide rail is configured to guide such that
the operating device is moved along the axial direction of the
camshaft as the camshaft is rotated on a state that the operating
pin contacts the guide rail.
4. The multiple variable valve lift apparatus of claim 1, wherein
the cam cap is positioned to surround an exterior circumference of
the zero cam in a case that the valve opening/closing device is
operated by the normal cam.
5. The multiple variable valve lift apparatus of claim 1, wherein
an oil passage is formed at the cam cap so as to supply oil for
lubrication to an exterior circumference of the journal.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to Korean Patent
Application No. 10-2015-0083556 filed Jun. 12, 2015, the entire
contents of which is incorporated herein for all purposes by this
reference.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to a multiple variable valve
lift apparatus. More particularly, the present invention relates to
a multiple variable valve lift apparatus to realize multiple valve
lifts which includes zero lift.
[0004] Description of Related Art
[0005] Generally, an internal combustion engine receives fuel and
air into a combustion chamber and generates power by combusting the
fuel and the air. Herein, an intake valve is operated by drive of a
camshaft, and air flows into the combustion chamber during when the
intake valve is open. In addition, an exhaust valve is operated by
drive of a camshaft, and air is exhausted from the combustion
chamber while the exhaust valve is open.
[0006] Meanwhile, optimal operations of the intake valve or the
exhaust valve are determined according to rotation speed of the
engine. That is, lift and open/close timing of the valves are
properly controlled according to rotation speed of the engine. A
variable valve lift (VVL) apparatus has been developed in which the
valves are operated for various lifts according to rotation speed
of the engine for realizing optimal operations of the valves
according to rotation speed of the engine. For example, there is a
cam shift type variable valve lift apparatus in which a plurality
of cams for operating the valves by each different lift are
provided to the camshaft, and the cam operating the valves is
selected according to conditions.
[0007] If a journal disposed between a cam and another cam is
formed to be lengthy along axial direction for cam shift in a
variable valve lift apparatus which is configured so that cams are
arranged in parallel with each other for operating two valves, it
is not easy that the variable valve lift apparatus is applied to a
small engine having a narrow gap between two valves.
[0008] The information disclosed in this Background of the
Invention section is only for enhancement of understanding of the
general background of the invention and should not be taken as an
acknowledgement or any form of suggestion that this information
forms the prior art already known to a person skilled in the
art.
BRIEF SUMMARY
[0009] Various aspects of the present invention are directed to
providing a multiple variable valve lift apparatus having
advantages of providing a simple composition and being applied to
an engine which has a narrow gap between two valves.
[0010] According to various aspects of the present invention, a
multiple variable valve lift apparatus may include a camshaft
rotating by driving of an engine, a cam portion formed in a
cylindrical shape having a hollow that the camshaft is inserted
into, rotating together with the camshaft, configured to move along
an axial direction of the camshaft, and forming a zero cam and a
normal cam, a valve opening/closing device configured to be
operated by at least one of the zero cam or the normal cam which
are formed at the cam portion, an operating device disposed on an
exterior circumference of the camshaft so as to move together with
the cam portion, and a solenoid configured to selectively move the
operating device along an axial direction of the camshaft, in which
a journal, which has a radius being equal to a radius of the zero
cam, may be formed at the cam portion such that a cam cap surrounds
an exterior circumference thereof.
[0011] The operating device may be formed in a cylinder shape
having a hollow that the camshaft is inserted into.
[0012] A guide rail may be formed at the operating device by a
groove shape to be extended along an external circumference, an
operating pin, which is selectively contacted to the guide rail,
may be disposed at the solenoid, and the guide rail may be
configured to guide such that the operating device is moved along
the axial direction of the camshaft as the camshaft is rotated on a
state that the operating pin contacts the guide rail.
[0013] The cam cap may be positioned to surround an exterior
circumference of the zero cam in a case that the valve
opening/closing device is operated by the normal cam.
[0014] An oil passage may be formed at the cam cap so as to supply
oil for lubrication to an exterior circumference of the
journal.
[0015] It is understood that the term "vehicle" or "vehicular" or
other similar terms as used herein is inclusive of motor vehicles
in general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g., fuel derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example, both
gasoline-powered and electric-powered vehicles.
[0016] The methods and apparatuses of the present invention have
other features and advantages which will be apparent from or are
set forth in more detail in the accompanying drawings, which are
incorporated herein, and the following Detailed Description, which
together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates an exemplary multiple variable valve lift
apparatus according to the present invention on a state of
realizing zero lift.
[0018] FIG. 2 illustrates an exemplary multiple variable valve lift
apparatus according to the present invention on a state of
realizing normal lift.
[0019] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
DETAILED DESCRIPTION
[0020] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that the present description is
not intended to limit the invention(s) to those exemplary
embodiments. On the contrary, the invention(s) is/are intended to
cover not only the exemplary embodiments, but also various
alternatives, modifications, equivalents and other embodiments,
which may be included within the spirit and scope of the invention
as defined by the appended claims.
[0021] FIG. 1 illustrates a multiple variable valve lift apparatus
according to various embodiments of the present invention on a
state of realizing zero lift.
[0022] As shown in FIG. 1, a multiple variable valve lift apparatus
1 according to various embodiments of the present invention
includes a camshaft 100, a cam portion 40, a solenoid 10, and
operating devices 30 and 50.
[0023] The camshaft 100 is a shaft which is rotated by rotation of
a crankshaft (not shown) of an engine. The camshaft 100 is
well-known to a person of ordinary skill in the art such that a
detailed description thereof will be omitted.
[0024] The cam portion 40 is a portion where cams 41, 42, 48, and
49 for operating an intake or exhaust valve 7 of an engine are
formed, and is formed in a hollow cylinder shape having a set
thickness. In addition, the camshaft 100 is inserted into the
hollow of the cam portion 40. Thus, an entire shape of the cam
portion 40 and the camshaft 100 is a shape such that the cam
portion 40 protrudes from an exterior circumference of the camshaft
100. Herein, the hollow of the cam portion 40 mat be formed in a
circular shape corresponding to an external circumference of the
camshaft 100. That is, an interior circumference of the cam portion
40 contacts an exterior circumference of the camshaft 100. Further,
an interior circumference of the cam portion 40 slides on an
exterior circumference of the camshaft 100 such that the cam
portion 40 is moved along an axial direction of the camshaft 100.
The cam portion 40 is disposed to rotate together with the camshaft
100. The composition with which the cam portion 40 is movable along
an axial direction of the camshaft 100 and the cam portion 40 and
the camshaft 100 are coupled with each other such that the cam
portion 40 and the camshaft 100 are rotated together can be
realized by types such as using a spline according to design of a
person of ordinary skill in the art.
[0025] The cam portion 40 is adapted to operate valves 7 disposed
at one cylinder. In addition, the cam portion 40 can be provided
for two valves 7 disposed at one cylinder. Herein, the valve 7 is
the intake valve or the exhaust valve.
[0026] The cam portion 40 includes a first zero cam 41, a first
normal cam 42, a second zero cam 48, a second normal cam 49, and a
journal 45.
[0027] The first and second normal cams 42 and 49 realize normal
lift that the valve 7 is repeatedly opened/closed by uniform lift
depending on the cam 42 and 49. In addition, the first and second
normal cams 42 and 49 may be formed in a general cam shape that an
exterior circumference of a cut-plane is formed in an oval shape
such that one end thereof is relatively further protruded to
compare with the other end thereof. Typically, the one end of the
cam is called "cam lobe", and the other end of the cam is called
"cam base".
[0028] The cam base is a base circle of a cam, a part of an
external circumference of the cam, which is formed in an arc shape
having a uniform radius. In addition, the cam lobe is a part of an
external circumference of the cam 42 and 49 which pushes the valve
opening/closing device 5 from when opening of the valve is started
to when closing of the valve is ended by rotation of the cam 42 and
49. Herein, the valve opening/closing device 5 is a device that one
end thereof is rolling-contacted with the cams 41, 42, 48, and 49
so as to be operated to open/close the valves by the rotation of
the cams 41, 42, 48, and 49. The valve opening/closing device 5,
which may be a roller swing arm, is well-known to a person of an
ordinary skill in the art such that a detailed description thereof
will be omitted.
[0029] The first and second zero cams 41 and 48 realize zero lift
that the valve 7 is not opened even though the cams 41 and 48
rotate. That is, the first and second zero cams 41 and 48 are
formed in a circle shape having an uniform radius so as to form
only cam base and do not form cam lobe.
[0030] That is, the normal lift of the valve 7 is realized when the
valve opening/closing device 5 is connected to rolling-contact the
normal cams 42 and 49, and the zero lift of the valve 7 is realized
when the valve opening/closing device 5 is connected to
rolling-contact the zero cams 41 and 48. In addition, the first and
second normal cams 42 and 49 or the first and second zero cams 41
and 48 for operating the valve 7 are selected according to movement
of the cam portion 40 along an axial direction of the camshaft
100.
[0031] The first zero cam 41 and the first normal cam 42 are formed
to be close to each other, and the second zero cam 48 and the
second normal cam 49 are formed to be close to each other. In
addition, the first zero cam 41 and the first normal cam 42 are
paired with each other so as to operate one valve 7, and the second
zero cam 48 and the second normal cam 49 are paired with each other
so as to operate the other valve 7.
[0032] The journal 45 connects the pair of the first zero cam 41
and the first normal cam 42 with the pair of the second zero cam 48
and the second normal cam 49. That is, the journal 45 is disposed
between the pair of the first zero cam 41 and the first normal cam
42 and the pair of the second zero cam 48 and the second normal cam
49, and the cam portion 40 is integrally molded. Herein, the
journal 45 is formed in a cylinder shape having a uniform radius,
and the radius of the journal 45 is equal to the radius of the
first and second zero cams 41 and 48.
[0033] The solenoid 10 is provided so as to transform rotational
motion of the camshaft 100 to rectilinear motion of the cam portion
40. That is, the cam portion 40 is rectilinearly moved along an
axial direction of the camshaft 100 according to rotational motion
of the camshaft 100 if the solenoid 10 is operated. Herein, the
solenoid 10 operated to on or off by electrical control of the
solenoid 10 that is well-known to a person of ordinary skill in the
art such that a detailed description thereof will be omitted.
[0034] The operating devices 30 and 50 are formed in a cylinder
shape having a hollow like the cam portion 40, and the camshaft 100
is inserted into the hollow of the operating devices 30 and 50 such
that the operating devices 30 and 50 are disposed on an exterior
circumference of the camshaft 100. In addition, the hollow of the
operating device 30 and 50 may be formed such that an internal
circumference of the operating devices 30 and 50 corresponds to an
external circumference of the camshaft 100. An external
circumference of the operating devices 30 and 50 is formed in a
circular shape having a uniform radius. Furthermore, an interior
circumference of the operating devices 30 and 50 slides on an
exterior circumference of the camshaft 100 such that the operating
devices 30 and 50 are moved along an axial direction of the
camshaft 100, and the operating devices 30 and 50 are adapted to
rotate together with the camshaft 100. That is, the operating
devices 30 and 50 are coupled with the camshaft 100 by types such
as using a spline.
[0035] The solenoid 10 may be separated to a zero lift solenoid 12
and a normal lift solenoid 14, and the operating devices 30 and 50
may be separated to a zero lift operating device 30 and a normal
lift operating device 50.
[0036] The zero lift operating device 30 is disposed at one end of
the cam portion 40. In addition, the zero lift operating device 30
is integrally formed with the cam portion 40 or is provided to move
together with the cam portion 40. Further, the zero lift operating
device 30 rotating together with the camshaft 100 is moved in one
direction along an axial direction of the camshaft 100 according to
the operation of the zero lift solenoid 12. Thus, the zero lift of
the valve is realized.
[0037] An operating pin 16 is disposed at the zero lift solenoid
12, and a guide rail 32 is formed at an external circumference of
the zero lift operating device 30 by a groove shape to be extended
along the external circumference. In addition, the guide rail 32
may be designed by a person of an ordinary skill in the art such
that the zero lift operating device 30 moves toward one direction
along an axial direction if the camshaft 100 rotates on a state
that the operating pin 16 is inserted into the guide rail 32.
[0038] The normal lift operating device 50 is disposed at the other
end of the cam portion 40. In addition, the normal lift operating
device 50 is integrally formed with the cam portion 40 or is
provided to move together with the cam portion 40. Further, the
normal lift operating device 50 rotating together with the camshaft
100 is moved in one direction along an axial direction of the
camshaft 100 according to the operation of the normal lift solenoid
14. Thus, the normal lift of the valve 7 is realized.
[0039] An operating pin 18 is disposed at the normal lift solenoid
14, and a guide rail 52 is formed at an external circumference of
the normal lift operating device 50 by a groove shape to be
extended along the external circumference. In addition, the guide
rail 52 may be designed by a person of an ordinary skill in the art
such that the normal lift operating device 50 moves toward the
other direction along an axial direction if the camshaft 100
rotates on a state that the operating pin 18 is inserted into the
guide rail 52.
[0040] FIG. 2 illustrates a multiple variable valve lift apparatus
according to various embodiments of the present invention on a
state of realizing normal lift.
[0041] As shown in FIG. 1 and FIG. 2, a cam cap 50 is disposed to
surround an external circumference of the journal 45 for preventing
that the camshaft 100 is escaped by rotation of the cams 41, 42,
48, and 49.
[0042] In case the zero lift of the valve 7 is realized, the cam
cap 20 is positioned on the exterior circumference of the journal
45, and in case the normal lift of the valve 7 is realized, the cam
cap 20 is positioned on the exterior circumference of both the
journal 45 and the second zero cam 48.
[0043] That is, as the journal 45 and the zero cam 41 and 48 have
equal radius, the second zero cam 48 can be moved to be surrounded
by the cam cap 20 without interference of the cam cap 20 when the
normal lift of the valve 7.
[0044] An axial direction length of the journal 45 may be designed
to be close a set thickness because the second zero cam 48 is moved
to be surrounded by without interference with the cam cap 20.
Therefore, the multiple variable valve lift apparatus 1 according
to various embodiments of the present invention can be applied to
an engine that a distance d between the two valves 7 which are
disposed at one cylinder is narrow. Herein, the degree that the
distance d between the two valves 7 is narrow may be close the sum
of the thickness of the cam cap 20 and a thickness of one pair of
cams 48 and 49.
[0045] Meanwhile, an oil passage 25 is formed at the cam cap 20 for
lubrication of the cam 41, 42, 48, 49. In addition, oil is supplied
to the exterior circumference of the journal 45 through the oil
passage 25. Further, oil is also supplied to the exterior
circumference of the second zero cam 48 when the normal lift of the
valve 7 through the oil passage 25. Therefore, oil for lubrication
is easily supplied to the lobe of the first normal cam 42 which is
positioned to be close to the journal 45 and the lobe of the second
normal cam 49 which is positioned to be close to the second zero
cam 48.
[0046] According to various embodiments of the present invention,
it is possible that an axial direction length of the journal 45 is
reduced as a diameter of the journal 45 is equal to a diameter of
the zero cam 48. In addition, fuel consumption can be improved as a
multiple variable valve lift apparatus 1 is able to apply to a
small engine having a narrow distance d between the two valves 7.
Further, lubrication effect may be improved as oil is easily
supplied to the lobe of the normal cam 42 and 49 through the oil
passage 25 formed at the cam cap 20.
[0047] For convenience in explanation and accurate definition in
the appended claims, the terms "upper" or "lower", "inner" or
"outer" and etc. are used to describe features of the exemplary
embodiments with reference to the positions of such features as
displayed in the figures.
[0048] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *